package com.bjsxt; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class TestInitServlet extends HttpServlet { private static final long serialVersionUID = 1L; @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.setContentType("text/html;charset=GBK"); PrintWriter out = resp.getWriter(); out.println(this.getServletConfig().getServletName()); java.util.Enumeration params = this.getServletConfig() .getInitParameterNames(); for (; params.hasMoreElements();) { String name = params.nextElement().toString(); String value = this.getServletConfig().getInitParameter(name); out.println(value); } out.close(); } }
<servlet> <servlet-name>TestInitServlet</servlet-name> <servlet-class>com.bjsxt.TestInitServlet</servlet-class> <init-param> <param-name>name</param-name> <param-value>小王</param-value> </init-param> <init-param> <param-name>gender</param-name> <param-value>男</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>TestInitServlet</servlet-name> <url-pattern>/servlet/TestInitServlet</url-pattern> </servlet-mapping> 输出:TestInitServlet 小王 男
有些朋友会发现在GenericServlet为什么要有两个init方法呢?
public void init()
A convenience method which can be overridden so that there's no need to call super.init(config).
void init(ServletConfig config)
Called by the servlet container to indicate to a servlet that the servlet is being placed into service.
如果不提供init()方法的话,我们如果重写init(config)又忘记写super.init(config)了的话,就会出错
实际上就是怕程序员忘记写super.init(config)
现在提供了init()方法了它说so that there's no need to call super.init(config).